| 摘要 |
PURPOSE: To obtain a polyester-based substrate for photography, forming a polyester having a specific melt electric resistance value into a film and stretching the film by an electrostatic impression method, slight in coloring, excellent in electrostatic adhesivity and transparency. CONSTITUTION: A polyester such as polyethylene-2,6-naphthalate, etc., having 6.0-7.0 melt electric resistance value shown by common logarithm in a molten state at 300 deg.C is made into a film at 20-120m/minute film forming and stretching rate by an electrostatic impression method so as to make an undrawn film having 0.45-2.5mm thickness. A metal chloride soluble in glycol and a nitrogen atom-containing hetero cyclic compound are added before starting of the polyester polycondensation reaction and then the polycondensation reaction is preferably carried out. |
